Remove unused variable

Author: rodrigowebjump

app/code/Magento/Customer/Test/Unit/Model/EmailNotificationTest.php

@@ -321,7 +321,6 @@ public function testPasswordReminder()
         $sender = 'Sender';
         $senderValues = ['name' => $sender, 'email' => $sender];
         $storeIds = [1, 2];
-        $defaultStoreId = reset($storeIds);
 
         $this->senderResolverMock
             ->expects($this->once())